The present invention relates to implantable medical devices. More particularly, the present invention relates to processing chronic physiological data from an implantable medical device (IMD) based on patterns of recurrence in the physiological data.
An important aspect of modern health care is the need to monitor the vital signs and other medical episodes and data associated with a patient, particularly those who have an IMD to treat an illness or medical condition. This monitoring has traditionally been performed by having a patient visit a hospital or clinic so that a programmer or a similar device can interrogate the IMD to gather and display the information that the IMD has stored.
Recent developments in monitoring technology have made it possible for a patient to upload data from an IMD to a remote location via a communication network such as the worldwide web, using a telephone connection or a similar type of connection to transmit the information from the IMD to the remote location. One system for this type of communication is the CareLink® network provided by Medtronic, Inc. of Minneapolis, Minn. The remote monitoring provided by such systems allows a patient with an IMD to reduce the number and frequency of visits to a hospital or clinic, by periodically uploading data for review by a physician or other medical personnel to determine whether further follow up analysis is necessary. This capability gives patients significantly greater freedom in their lifestyle, and has brought a higher quality of life to many patients.
For data that is best characterized by temporal patterns or information (e.g., atrial arrhythmia burden data), the timing of scheduled reporting of data may fail to accurately characterize the data if it has a period of repetition longer than the reporting interval. In these cases, diagnostic parameters extracted from the data may differ significantly from the true value of the parameters. In addition, it is possible that more long-term patterns of variability will not be observed if changes in the temporal patterns are not monitored. For example, a change in a patient's condition may not be observed if the clinician is unable to properly characterize the data provided by the IMD. Furthermore, resources in the IMD (e.g., memory) may be used inefficiently if temporal information in the data is not taken into consideration when processing data.